Full-fat silkworm chrysalis meal as well as preparation method and application thereof

Abstract

The invention provides full-fat silkworm chrysalis meal as well as a preparation method and application thereof, and relates to the technical field of food processing. The invention discloses a preparation method of full-fat silkworm chrysalis meal, which comprises the following steps: pulping fresh cocoon silk reeling silkworm chrysalis or / and fresh and alive silkworm chrysalis at low temperature, removing silkworm chrysalis skin, adding a proper amount of cyclodextrin and a pH regulator, carrying out pulse type emulsification treatment at low temperature by adopting a high-speed shearing emulsifying machine, and then freeze-drying to obtain the full-fat silkworm chrysalis meal. The full-fat silkworm chrysalis meal is high in activity, high in protein-grease fusion degree, good in stability and free of fishy smell.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, in particular to full-fat silkworm pupa powder and a preparation method and application thereof. Background Art

[0002] Silkworm pupae are the only insect-based food item included in the Ministry of Health's "List of Food Resources Managed as Ordinary Foods." Silkworm pupae represent the most significant stage of metamorphosis and functional changes in silkworms. They are not only rich in nutrients like protein and unsaturated fatty acids, but also contain numerous bioactive components, such as active enzymes, peptides, flavonoids, and alkaloids. These synergistic effects give silkworm pupae potent antioxidant, immune-enhancing, and memory-enhancing properties, making them promising for development. However, these active ingredients are relatively unstable and easily destroyed during processing, resulting in decreased activity and the development of off-flavors. Furthermore, the poor protein-fat compatibility of full-fat silkworm pupa powder makes it susceptible to oil seepage, rancidity, and the production of harmful substances, limiting the development of products made from silkworm pupae.

[0003] Currently, silkworm pupae are typically defatted and further purified to produce silkworm pupae protein or silkworm pupae oil for food use. This not only results in the loss of significant amounts of active ingredients, but also complicates the processing and is costly. For example, CN 102669381 A undergoes multiple water treatments, retaining only insoluble protein and losing some nutrients. Summary of the Invention

[0004] The present invention aims to provide a method for preparing full-fat silkworm pupa powder, which not only better retains the nutritional components in silkworm pupae, including soluble protein and oil, but also adopts low-temperature high-speed stirring and cyclodextrin inclusion to prepare full-fat silkworm pupa powder with good stability; another object of the present invention is to provide full-fat silkworm pupa powder with stable performance. Technical Solution

[0005] In a first aspect, the present application provides a method for preparing full-fat silkworm pupa powder, comprising the following steps: 1) taking fresh cocoon silkworm pupae and / or fresh live silkworm pupae, refrigerating them to -2-15°C, beating them, separating the silkworm pupae skins, and obtaining silkworm pupae pulp A; 2) adding cyclodextrin at a silkworm pupa mass fraction of 0.1-10 wt% to silkworm pupa slurry A at -2-15°C, adjusting the pH to 4.0-11.0 with a pH regulator, and then performing shear homogenization at a speed of 8000-20000 r / min to obtain silkworm pupa slurry B; 3) The silkworm pupa pulp B is freeze-dried and crushed to obtain silkworm pupa powder.

[0006] Furthermore, the refrigeration temperature in step 1) is 0-5°C; and the operating temperature in step 2) is 0-5°C.

[0007] Furthermore, the silkworm pupae are fresh silkworm pupae.

[0008] When the silkworm pupa is damaged, a series of rapid enzymatic reactions will occur to produce a large amount of callus tissue to resist bacterial invasion and tissue repair. This is the main mechanism for browning during processing, which leads to a decrease in active ingredients and the production of harmful substances such as small molecular organic amines, aldehydes, and acids. Pre-freezing to a low temperature of -2-15°C, preferably 0-5°C, inhibits enzyme activity, and then grinding is performed. The callus process is almost stopped, which maintains the loss of active substances and avoids the loss of active substances and the production of harmful substances.

[0009] Furthermore, the pH adjuster in step 2) is any one of citric acid, acetic acid, lactic acid, hydrochloric acid, sodium bicarbonate, sodium carbonate, sodium acetate, sodium citrate or sodium hydroxide, or a combination thereof.

[0010] Furthermore, in step 2), the homogenization and emulsification treatment is performed at a rotation speed of 14,000-18,000 r / min, homogenizing for 10-60 seconds followed by a 1-10 second pause, and repeating the operation for a total treatment time of 5-30 minutes.

[0011] Furthermore, the amount of cyclodextrin used in step 2) is 2-5 wt% of the mass of silkworm pupae.

[0012] In order to break up the insoluble skeleton protein of silkworm pupae, achieve efficient fusion of protein and oil, improve the stability of major active ingredients such as small molecules such as active peptides, polyphenols, flavonoids, unsaturated fatty acids, and better retain nutrients, high-speed (8000-20000 r / min) shear homogenization is adopted at low temperature of -2-15℃.

[0013] Excessive cyclodextrin will increase the viscosity of the system and worsen the inclusion effect.

[0014] Furthermore, the cyclodextrin is β-cyclodextrin.

[0015] Furthermore, in step (3) freeze drying, the silkworm pupa pulp B is pre-frozen at -50--40°C; under the conditions of vacuum degree ≤10Pa and cold trap temperature -50°C, the temperature is gradually increased to 25-40°C for sublimation drying, and dried to a water content of ≤5%.

[0016] In a second aspect, the present application provides a full-fat silkworm pupa powder obtained by the preparation method of the present application.

[0017] In a third aspect, the full-fat silkworm pupa powder obtained by the method of the present application is used as a raw material for preparing foods having antioxidant function and / or enhancing immune function and / or assisting in improving memory function.

[0018] Beneficial effects: 1. The present invention uses the method of beating silkworm pupae at a low temperature, and adopts cyclodextrin to encapsulate the full-fat silkworm pupae powder slurry under low temperature and high-speed shearing conditions, which better preserves the nutritional components in silkworm pupae, including soluble protein, insoluble protein and oil; the mechanical force of high-speed shearing destroys the spatial structure of the enzyme to inactivate it, further inhibits related reactions, and at the same time breaks up the insoluble skeleton protein of silkworm pupae, thereby realizing efficient fusion of protein and oil. The main active ingredients such as active peptides, polyphenols, flavonoids, and unsaturated fatty acids have a small molecular weight and are stable in structure and can be preserved. The full-fat silkworm pupae powder is prepared by high-speed shearing treatment under low temperature conditions, which can effectively maintain the pharmacological activity of silkworm pupae powder, significantly improve the fusion of silkworm pupae protein and oil, and has good stability and no fishy smell. 2. Further select fresh silkworm pupae, preferably refrigerated at 0-5℃, to inhibit the activity of enzymes. Then grind the silkworm pupae, and the healing process will almost stop, reducing the loss of nutritional active substances and the generation of harmful substances. DETAILED DESCRIPTION

[0019] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to specific embodiments.

[0020] Example 1, a method for preparing full-fat silkworm pupa powder, comprising the following preparation steps: 1) taking fresh cocoon silkworm pupae and / or fresh live silkworm pupae, refrigerating them to -2-15°C, beating them, separating the silkworm pupae skins, and obtaining silkworm pupae pulp A; 2) adding cyclodextrin at a silkworm pupa mass fraction of 0.1-10 wt% to silkworm pupa slurry A at -2-15°C, adjusting the pH to 4.0-11.0 with a pH regulator, and then homogenizing and emulsifying the mixture at a speed of 8000-20000 r / min to obtain silkworm pupa slurry B; The homogenization emulsification treatment method is to emulsify at a rotation speed of 14000-18000 r / min, emulsify for 10-60 seconds, pause for 1-10 seconds, and repeat the operation. The total treatment time is 5-30 minutes.

[0021] 3) The silkworm pupa pulp B is freeze-dried and crushed to obtain silkworm pupa powder.

[0022] Freeze drying is to pre-freeze the silkworm pupa pulp B at -50--40°C; under the conditions of vacuum degree ≤10Pa and cold trap temperature -50°C, gradually increase the temperature to 25-40°C for sublimation drying, and dry to a water content of ≤5%.

[0023] Example 2, a method for preparing full-fat silkworm pupa powder, comprising the following preparation steps: 1) Take 10 kg of fresh live silkworm pupae, rinse with running water to remove surface impurities, freeze in a freezer to -2°C, maintain the temperature at 2±1°C, beat, and pass through a nylon sieve to remove the pupal skin to obtain silkworm pupal slurry A.

[0024] 2) Adjust the pH of silkworm pupa slurry A to 7.0 with a citric acid-sodium citrate solution. Then, add cyclodextrin (β-cyclodextrin) at a 3.0% mass fraction of silkworm pupae and stir evenly. Maintain the slurry temperature at 2±1°C and emulsify it in a high-speed shear emulsifier at 11,000 r / min. Repeat 10 times with a cycle of "emulsification for 30 seconds and rest for 3 seconds" to obtain silkworm pupa slurry B.

[0025] 3) Pour the silkworm pupa slurry B into a stainless steel dish (8±2 mm thick), pre-freeze at -40°C, freeze-dry, and pulverize to obtain full-fat silkworm pupa powder 1, which is then packaged in PVC bags at 100 g / bag.

[0026] Comparative Example 1: A method for preparing full-fat silkworm pupa powder: Fresh, live silkworm pupae are beaten at 25°C, passed through a nylon sieve, and the pupa skins are removed to obtain a pupa slurry. The pupa slurry is poured into a stainless steel plate (5-10 mm thick), vacuum-dried at 60°C, and pulverized to obtain full-fat silkworm pupa powder, which is then packaged in PVC bags at 100g per bag.

[0027] 1. Oil embedding efficiency ME: Accurately weigh 5 g of full-fat silkworm pupa powder and extract it in a Soxhlet apparatus at 75°C for 8 h. After extraction, dry the remaining residue in an oven at 65°C to a constant weight. The difference between the original weight and the original weight is the total oil content. Calculate the total oil content per gram of product and record it as OT.

[0028] Accurately weigh 0.5g of each full-fat silkworm pupa powder sample and place it on filter paper lined with a Büchner funnel. Slowly drip a certain amount of petroleum ether into the silkworm pupa powder sample for 2 minutes. Rinse the funnel with a large amount of petroleum ether, allowing the oil dissolved in the petroleum ether to flow through the funnel into a small beaker of constant weight. Place it in an 80°C constant temperature oven to dry to a constant weight, then accurately weigh it. The difference in mass before and after the beaker is the surface oil content of 0.5g of product. Calculate the surface oil content per gram of product as OS. Calculate the oil embedding efficiency ME according to the following formula: ME = (OT - OS) / OT × 100%. The test results are shown in Table 1.

[0029] 2. Antioxidant activity 0.1 g of silkworm pupa powder sample was taken, 1 mL of pre-cooled 80% ethanol and steel balls were added, and the mixture was placed in a tissue grinder for homogenization; ultrasonic extraction was performed at 60°C and 200W for 30 min (with oscillation mixing every 5 minutes); the sonicated sample was placed in a centrifuge at 12000 rpm for 10 min, and the supernatant was collected. The antioxidant activity of the examples and comparative examples was determined using a total antioxidant capacity (FRAP) assay kit. The test results are shown in Table 1.

[0030] 3. The smell of silkworm pupa powder: One bag of full-fat silkworm pupa meal from the Examples and Comparative Examples was placed in a constant-temperature incubator at 40°C ± 2°C. Samples were taken at 0, 30, and 90 days. The bags were opened and smelled for odor scoring. The intensity of the fishy odor was scored based on the following: 7.6-10 for a characteristic silkworm pupa aroma with no or a slight fishy odor; 5.1-7.5 for a characteristic silkworm pupa aroma with a slight fishy odor; 3.1-5 for a distinct fishy odor; and 0-3 for a strong fishy odor and a rancid odor. Ten independent testers independently scored the samples and calculated the average. The test results are shown in Table 1.

[0031] 4. Peroxide value: Accurately weigh 50 g of the full-fat silkworm pupa powder of the 90-day embodiment and the comparative example in Example 4, and use the first method of GB5009.227-2023 "National Food Safety Standard for Determination of Peroxide Value in Food" to measure the peroxide value. The test results are shown in Table 1.

[0032] Table 1. Properties of full-fat silkworm pupa powder obtained by the methods of Examples and Comparative Examples

[0033] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for preparing full-fat silkworm pupa powder, characterized in that: The steps include: 1) taking fresh cocoon silkworm pupae and / or fresh live silkworm pupae, refrigerating them to -2-15°C, beating them, separating the silkworm pupae skins, and obtaining silkworm pupae pulp A; 2) adding cyclodextrin at a silkworm pupa mass fraction of 0.1-10 wt% to silkworm pupa slurry A at -2-15°C, adjusting the pH to 4.0-11.0 with a pH regulator, and then performing shear homogenization at a speed of 8000-20000 r / min to obtain silkworm pupa slurry B; 3) The silkworm pupa pulp B is freeze-dried and crushed to obtain silkworm pupa powder.

2. The preparation method according to claim 1, wherein Step 1) The refrigeration temperature is 0-5°C; The operating temperature in step 2) is 0-5°C.

3. The preparation method according to claim 1 or 2, wherein The silkworm pupae are fresh and living silkworm pupae.

4. The preparation method according to claim 3, wherein Step 2) The shear homogenization treatment is carried out at a rotation speed of 14000-18000 r / min, homogenizing for 10-60 seconds, followed by a rest period of 1-10 seconds, and repeating the operation for a total treatment time of 5-30 minutes.

5. The preparation method according to any one of claims 1 to 2 and 4, characterized in that: The amount of cyclodextrin used in step 2) is 2-5 wt% of the mass of silkworm pupae.

6. The preparation method according to claim 5, wherein The cyclodextrin is β-cyclodextrin.

7. The preparation method according to any one of claims 1 to 2, 4 and 6, characterized in that: Step 3) freeze drying is to pre-freeze the silkworm pupa slurry B at -50-40°C; under the conditions of vacuum degree ≤10Pa and cold trap temperature -50°C, gradually increase the temperature to 25-40°C for sublimation drying, and dry to a water content of ≤5%.

8. Full-fat silkworm pupa powder obtained by the preparation method according to any one of claims 1 to 7.

9. The full-fat silkworm pupa powder according to claim 8 is used as a raw material for preparing food having antioxidant function and / or enhancing immune function and / or assisting in improving memory function.

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